The most common reason for USB-eLicenser (dongle, formerly named Steinberg Key), Soft-eLicenser and/or license related problems is an outdated or corrupted eLicenser Control Center (eLCC) installation. So if an USB-eLicenser or a specific license on it is not recognized, or you get any eLCC error messages when starting your Steinberg sequencer, you should download and install the latest eLicenser Control Center at first. In case the installation fails, try to install again after you've unplugged the USB-eLicenser.

Go to "User Home/Library/Preferences" and locate the folder which is named the same as your sequencer, for example "Cubase 8.5". This folder contains all preference files of your sequencer. Since Mac OS X 10.7 (Lion), the user's Library folder is hidden by default. Here is how to access it: In the menu bar of Mac OS X click on 'Go'. While the menu is folded out holding down the [alt] key (options) will show the 'Library' entry.

Rename it (for example, from 'Cubase 8.5' to 'xCubase 8.5') in order to hide it from the sequencer. The folder will only be hidden safely, if the change will be done before the original folder name.

If you find folders of previous versions of your program, make sure to hide or remove them, too.

Next time you start the sequencer it will create a new folder with fresh preferences and default settings - which hopefully fixes the problem you've experienced.

Please note: If you find folders of previous Steinberg sequencer installations, make sure to hide them, too, by renaming or removing them. Otherwise the sequencer would try to comply with them when creating fresh preferences. And exactly this could be the source of any error.

Initialising the sequencer's preferences does not necessarily mean that you lose all settings. For example if you have defined your own set of key commands that you want to keep you can replace the corresponding file ("Key Commands.xml") in the freshly created folder by a copy of the same file taken from the folder you've disabled by renaming.

Alternative ways: Instead of renaming it you also can move the preferences folder of your sequencer from the User/Library/Prefences folder to another place, for example the Desktop. You even can simply trash it if you are sure that your user settings are not that hard to rebuild. Another approach: Since in many cases the file Defaults.xml will be the trouble maker you could also try if renaming only this particular file already solves the problem.

Making a backup of the preferences obviously is a good idea, especially when you customize a lot. And it's easy: Simply right-click on the preferences folder of your Steinberg sequencer within User Home/Library/Preferences and select Create Archive of (Tiger) or Compress (Leopard) from the contextual menu. This creates a Zip file that you can always fall back on if you need to reset the preferences to your preferred settings. Of course you could as well keep a common copy of the folder at a location of your choice.

Check if your Steinberg sequencer is up-to-date. A current version might include a solution for the problem you are experiencing. Updates are available on the download page. The "Version History" document on the same page will tell you which issues have been addressed.

Your Steinberg sequencer is dependent on flawlessly working audio and MIDI interfaces. Many problems are caused by bad device drivers. Check the homepage of your gear's manufacturer for updates. If you have installed drivers from a CD-R that came with an interface you can almost be sure that they are fatally outdated.

Use the Activity Monitor of Mac OS X to get an overview of the memory usage. In case less than 500 MB free memory are available, the overall performance of the system as well as the stability of single programs might be reduced severely.

On a 64-bit system, you should make sure to run the 64-bit version of your Steinberg program and additionally installed plug-ins. Otherwise, maximally 4 GB of the installed memory can be used and memory issues might occur, even though the system memory ressources don't seem to be exhausted. Read more...

Apart from the size of the installed memory modules, the amount of free memory depends on the individual way of working and the loaded project. In case your system is short of memory, you have the following options:

Quit all redundant programs. For example, an internet browser running in background with some opened tabs can easily consume 1 GB RAM or more. In case of doubt, use Activity Monitor to get an overview of the memory allocation.

Sample-based VST Instruments are the biggest memory consumers within a project. Therefore, you should only use as many VST Instruments as necessary. If possible, do not use multiple instances of the same VST Instrument. Instead, use several MIDI tracks to address a single instance of the same instrument.

If you do not want to confine yourself to a memory-saving way of working, you will need to expand the installed memory, which might require a switch from 32-bit to 64-bit.

If your Steinberg sequencer hangs or quits during the start up or while loading a specific project file, it is likely that an installed VST plug-in is causing trouble. This is how you can verify if a specific plug indeed is sabotaging Cubase.

Quit your Steinberg sequencer.

Go to Library/Audio/Plug-Ins and locate the folders 'VST' and 'VST3'. These are the default locations for VST (VST2) and VST3 plug-ins in Mac OS X. (To keep it simple, these instructions only take the default locations into account. You might need to consider additional plug-in folders. Read more on VST plug-in locations... )

Create two new folders at a location of your choice, for example in the Plug-Ins folder or on the Desktop. Name the new folders 'VST quarantined' and 'VST3 quarantined'. (Any other name will do it, too.)

Move the plug-ins from 'VST' to "VST quarantined" and from 'VST3' to 'VST3 quarantined'. Make sure you don't copy them! The plan is to emtpy the original plug-in folders VST and VST3. A convenient way to achieve this:

Select the plug-ins you want to move.

Press cmd + C to copy them to the clipboard.

Go to the destination folder, for example 'VST quarantined'.

To paste the plug-ins, press cmd + alt + V. This will move the plug-ins instead of copying them.

Once the folders VST and VST3 under Library/Audio/Plug-ins are empty, restart the sequencer and, if necessary, load the problematic project.

If the problem persists you know that it is obviously not related to a VST plug-in. In this case, just restore the original situation by puttting the quarantined plug-ins back to their original locations.In case moving the plug-ins did the trick, the source of error obviously is located in one of the quarantine folders. In order to find out the bad guy, move the most suspicious plug back to the original plug-in folder. Restart your Steinberg sequencer and see if it still runs correctly. Repeat moving plug-ins and restarting the sequencer until you've finally isolated the trouble maker. In case you have a lot of plug-ins installed moving half of them at a time might speed up the search.